A. Field of Invention
This invention pertains to the art of methods and apparatuses regarding protective equipment for vehicles, and more specifically to a dock bumper to be affixed to a trailer or other vehicle to minimize damage to the vehicle upon impacting another object.
B. Description of the Related Art
As trailers are backed into a loading dock to be loaded or unloaded, the truck driver relies primarily on mirrors to determine the proximity of the back end of the trailer to the loading-dock wall. For long trailers, this is a difficult task that often results in the back end of the trailer striking the terminal wall of the loading dock. Once such contact is made, the truck driver knows that the trailer is sufficiently close to the entrance of the loading dock to permit forklifts and other loading vehicles to enter the back of the trailer from the loading dock to insert or remove cargo.
It is known to provide dock bumpers on the back end of trailers adjacent to the entrance of the trailer's cargo area to absorb some of the force imparted on the trailers as they strike the wall of a loading dock. This way, as the back of the trailer strikes the wall, at least some of the forces exerted on the back of the trailer are dissipated by the dock bumpers to minimize damage to the back of the truck. As shown in FIG. 1, conventional dock bumpers 2 provided on the back end of trucks 3 are vertically-elongated structures that extend well below the lowest portion of the truck sill 4 or trailer frame relative to the ground, as shown in FIG. 1. Even with a triangular support 5 extending from the underside of the truck sill 4 to further support the overhanging portion of conventional dock bumpers 2, the conventional dock bumpers 2 still extend well beyond the lowermost surface of the support 5. This results in a cantilevered extension 6 that protrudes downwardly towards the ground and is not sufficiently supported to withstand impacts with low-lying objects.
Still referring to FIG. 1, the force from such an impact between the cantilevered extension 6 of a conventional dock bumper 2 and a low-lying object such as a curb in the direction of arrow 7 tends to impart a rotational force on the dock bumper 2. The rotational force causes rotation of the dock bumper 2 such that the cantilevered extension 6 is forced beneath the truck sill 4 or trailer frame. And since the dock-bumper 2 is a generally-rigid body, the non-cantilevered portion of the dock bumper 2 abutted against the truck sill 4 or trailer frame is forced in the opposite direction as shown by arrow 8. Movement of the non-cantilevered portion of the conventional dock bumper in this direction causes extension of the truck bed, body damage, and other harm that is expensive to repair.
Accordingly, there is a need in the art for a dock bumper that will minimize damage to a truck and trailer in the event of an impact between the dock bumper and a low-lying object. Such a dock bumper can absorb at least a portion of the force exerted on the back of the truck when contacting a loading-dock wall, and include features that respond to impacts with low-lying objects in a manner that minimizes the transmission of forces exerted on the back of the truck.